Within five years, Schumann wrote four great piano works connected to the fiction of E. T. A. Hoffmann.

They’re strikingly different from one another. And if there was a rule or expectation, Schumann would upend it. Not from wilfulness: in each case, it’s creative and revelatory.

Schumann said of his 1835-37 Carnaval that it ‘shows the whole crazy business of the carnival of the imagination’.

Its ordering principle is disorder, its centre the centrifugal.

Its famous Sphinxes are a carnivalesque inversion of traditional thematic development. They show no progressive thematic transformation or development, no deeper unity in surface diversity. They just sit on varied themes, parading a static surface uniformity on top of those themes’ underlying diversity: fixed masks on top of individual, mobile faces.

John MacAuslan is an independent scholar who holds a PhD in music. He worked for many years in Her Majesty's Treasury, the National Gallery and as a Civil Service Commissioner, as well as working for the NGO War Child....